If your dentist had their way, they'd like to see you change your toothbrush every three to four months. That's a lot of plastic that goes straight to landfill as you throw away your shaggy brush.
According to the World Wildlife Fund, around 3.5 billion throwaway plastic toothbrushes – usually made from polypropylene and nylon which can take up to 500 years to break down in landfill – are bought each year around the world. The vast majority will end up as plastic pollution.
But several more sustainable alternatives are emerging, particularly brushes made from bamboo and cornstarch, or others that have replaceable heads to minimise plastic waste. But how green are they, really?
Brushes made with bamboo handles are everywhere these days. You can buy them at Coles ($4), Woolworths ($8 for four), or Kmart ($6 for two) as well as direct from specialist online subscription services like Bamkiki and Toothcrush. Bamboo is generally considered to be an eco-friendly alternative to plastic as it's fast-growing and breaks down relatively easily in compost.
Bamboo is generally considered to be an eco-friendly alternative to plastic as it's fast-growing and breaks down relatively easily in compost
Toothcrush has broken down its product's environmental cred compared to plastic toothbrushes – taking into account CO2 emissions from transport and recyclability of packaging – and claims that an annual Toothcrush subscription is 18 times less damaging to the environment than someone who buys four plastic toothbrushes per year.
One word of caution: each of these brands' toothbrushes have nylon bristles. They are still used on most brushes on the Australian market, and are still a form of plastic waste that takes centuries to decompose. See 'recycling' section below.
Another increasingly popular material is cornstarch, like the toothbrush from Swedish brand The Humble Co ($3.38 from Smile Boosters).
Like bamboo, it's biodegradable, but it's less porous and so less likely to become "smelly" like bamboo can, according to Bare by Bauer, who also sells a cornstarch toothbrush for $4.50 plus shipping.
Cornstarch brushes are also available at Kmart in a two-pack for $6.00. Their version comes with charcoal-infused bristles, said to act as an antibacterial agent to keep the brush cleaner.
Image: Gaia Guy.
Boar bristle toothbrushes
One for the hardcore eco warriors, boar bristle toothbrushes are a fully biodegradable alternative to nylon bristles.
However, they involve 'harvesting' the bristles from an animal, something that's unlikely to sit well with anyone concerned for animal welfare (or who simply doesn't love the idea of putting pig hair in their mouth).
They can be hard to find but there are a few on the market, mostly sold overseas. One manufacturer is Gaia Guy.
Electric toothbrush fans have been replacing the plastic heads on their brushes since they were first invented, but now regular manual toothbrushes are getting in on the head-swap action.
The Colgate Infinity starter pack, which includes two replaceable plastic heads, sells for $30 at stores including Woolworths and Big W (replacement heads are $8.40 for a two-pack).
It has a sturdy aluminium handle; something that should please anyone who finds bamboo handles a bit flimsy, and Colgate says it means using 80% less plastic than fully-plastic alternatives when you stick with it over time.
Oral B's version is called 'Clic' and also retails for $30 at Woolworths. It claims to waste 60% less plastic than a fully-disposable toothbrush when used over two years.
Image: A Good Company.
Bamboo electric toothbrush heads
A Good Company in Sweden has even found a way to make electric toothbrushes more environmentally friendly, creating a line of bamboo heads that fit conventional electric toothbrushes including Oral B and Philips Sonicare. A pack of four starts at $32 plus shipping.
Sonicare-compatible bamboo electric toothbrush heads are also available from sites such as Booheads (two-pack from $14.91) and The Sustainable Tomorrow (two-pack from $13.92).
What about recycling?
Here's the tricky bit. If you simply throw your bamboo or cornstarch toothbrushes into your regular bin, you've basically wasted their biodegradable properties.
"If they are disposed of in landfill they will degrade in an anaerobic environment and create the pollutant methane," says Dr Peter Cass, Principal Research Scientist of Polymeric Biomaterials Chemistry at the CSIRO.
If you simply throw your bamboo or cornstarch toothbrushes into your regular bin, you've basically wasted their biodegradable properties
A much more earth-friendly option is to dispose of them in your home compost where they will break down into organic matter – eventually.
"They will also degrade in the environment… but this will take considerably longer and require a moist environment," says Dr Cass says.
But what about those bristles?
Nylon is still a plastic and can't be added to compost. Most bamboo toothbrush manufacturers suggest you snap the heads off your brushes or pull the bristles out with pliers before you add the handle to your compost bin.
Many also indicate their bristles are 'recyclable' – but not so fast. It's virtually impossible to find somewhere in Australia that will happily recycle them, particularly because they're so small.
Nylon bristles are far too small to be captured in the right waste stream during the recycling processLiam Taylor, Planet Ark
"Nylon is Code 7 'other' plastic, which can be recycled depending on the capabilities of local recyclers, but not always. More importantly, bristles are far too small for them to be captured in the right waste stream during the recycling process," says Liam Taylor, communications manager of Planet Ark. "Best advice would be to remove bristles and put them in the waste bin."
So you're still creating plastic waste with bamboo toothbrushes, just not as much as with 100% plastic toothbrushes.
Repurpose your toothbrush
Rather than throwing away your toothbrush – plastic, bamboo or cellulose – as soon as it gets shaggy, consider giving it a second life.
"Toothbrushes actually make great tools for cleaning a host of diverse items and small or hard-to-reach areas and crevices," says Taylor.
Use them to clean jewellery, grout, shoe soles, faucets, computer keyboards and even cheese graters. Just make sure you've given them a good wash first – no one wants bits of left-behind food stuck in their laptop keys.
Still attached to plastic? This recycling service could help
Can't give up the sturdiness and convenience of your plastic toothbrush but want a way to give it an earth-friendly end-of-life?
Terracycle offers an oral care recycling program that turns toothpaste tubes and caps, manual toothbrushes, electric toothbrush heads, toothbrush and toothpaste tube plastic packaging and floss containers into hard plastic that can be reused by manufacturers. There's also a separate program for recycling electric toothbrushes.